Where to plug in solar if we install ourselves

LaLaLisa · 09-17-2021, 03:14 PM

Hey Gang,
We are considering installing solar on our GT7 36D. It has the hookup, or so we were told, but we’re having trouble finding any information about how to do this. Any ideas from some of you with the identical house on wheels? Thanks!

**Cdefrees** · 09-20-2021, 10:00 AM

LaLaLisa,

I believe your coach has a Furrion plug in the wet bay. I'm not sure how much solar you are wanting to add? The plug we have on your coach will only handle 100 watts. If you are wanting more... the best way is to run the wires behind the refer down to your batteries. Hope this helps

mjbenedict · 09-20-2021, 10:27 AM

You cannot connect solar panels directly to batteries, you must have a solar controller (charger). The plugs on the sides of RVs are just a cable connected to the battery with a fuse for protection. They make "suitcase" solar panels with built-in controller to connect to this port.
That said, if you are placing panels on the roof you will want to mount a solar controller inside your rig near the battery. You will need to calculate how much solar you want and make sure the cables are the right size for the job. The controller can connect directly to the battery with the proper protection inline (fuse or breaker).
All solar panels wire to a controller/charger which is wired to the batteries with proper protection on all circuits.

ScottBrownstein · 09-20-2021, 11:20 AM

I suspect that your rig is designed pretty much like mine. You have a residential reefer, probably have 4 batteries in the basement under the big slide. Converter and power cord in the rear bay on the driver's side. Many run the cabling down through the refrigerator roof vent, but you have none. My recommendation is to do a roof penetration over the wardrobe in the bedroom and run a conduit straight down into the electrical bay below and run a couple pair of PV cables down to the electrical bay while you are at it. Mount the controller in the electrical bay and run a couple of #4 or #6 cables up the driver's side to the house battery bay. Of course you need appropriate fuses.

mnoland30 · 09-21-2021, 07:00 AM

If you're going with more than 100 watts (which you should with residential fridge), Google 12v voltage loss and find a table that tells you the voltage drop based on length of wire. You want your voltage loss to be in the 2-3% range. The voltage to the charge controller has to be high enough to allow 14.2v or higher (depending on your battery). If your wires are too small, you'll never get a full charge on your battery.

I didn't want to do a roof penetration, so I ran flexible plastic conduit down the side of mine. If I were going to do a penetration, I'd use two 90 degree elbows so the wires run up into the conduit (take a look at the power line going into your house). I'd also purchase flashing to put around the conduit to make a better seal.

ScottBrownstein · 09-21-2021, 07:07 AM

Quote:

Originally Posted by mnoland30

If you're going with more than 100 watts (which you should with residential fridge), Google 12v voltage loss and find a table that tells you the voltage drop based on length of wire. You want your voltage loss to be in the 2-3% range. The voltage to the charge controller has to be high enough to allow 14.2v or higher (depending on your battery). If your wires are too small, you'll never get a full charge on your battery.

I didn't want to do a roof penetration, so I ran flexible plastic conduit down the side of mine. If I were going to do a penetration, I'd use two 90 degree elbows so the wires run up into the conduit (take a look at the power line going into your house). I'd also purchase flashing to put around the conduit to make a better seal.

Best way to do that is to drill down from the roof and insert a plastic conduit that sticks up above the roof surface by maybe 3/8 inch. Seal around the conduit at the roof surface and then drill a clearance hole in the bottom of an exterior plastic box. Drill a small weep hole in the low side of the plastic box and then cement the box to the roof and seal the conduit inside the box. You can then use glands designed for PV wire in the sides of the box and secure the top with stainless screws and the supplied gasket. No real way for that to leak.

Get a charge controller that has remote sense and battery temperature feedback so the battery voltage applied is measured at the battery bank and not at the controller. Most controllers support these features. If you are using less than 400 watts or so, I recommend the Bogart SC2030 PWM solar controller, which supports both of these features.

NXR · 09-21-2021, 08:08 AM

What is the intended use for solar? Just to keep the batteries topped off in storage? To boondock for days at a time or what?

It's not a question you asked however I would use an MPPT solar controller, not a PWM controller. An MPPT controller can "harvest" more power from your solar array because it's more efficient. If you use a PWM controller some of the dollars you put into sizing your solar array are wasted. That means you need to buy more solar to make up for the efficiency loss in a PWM controller.

https://www.victronenergy.com/blog/2...r-pwm-or-mppt/

Ray

ScottBrownstein · 09-21-2021, 08:46 AM

Quote:

Originally Posted by NXR

What is the intended use for solar? Just to keep the batteries topped off in storage? To boondock for days at a time or what?

It's not a question you asked however I would use an MPPT solar controller, not a PWM controller. An MPPT controller can "harvest" more power from your solar array because it's more efficient. If you use a PWM controller some of the dollars you put into sizing your solar array are wasted. That means you need to buy more solar to make up for the efficiency loss in a PWM controller.

https://www.victronenergy.com/blog/2...r-pwm-or-mppt/

Ray

In general that may be true. However, for small installations which would be low voltage panels, there is a marginal difference between PWM and MPPT. That is why I said 400 watts or less.

NXR · 09-21-2021, 08:42 PM

Quote:

Originally Posted by ScottBrownstein

In general that may be true. However, for small installations which would be low voltage panels, there is a marginal difference between PWM and MPPT. That is why I said 400 watts or less.

Thanks for the clarification.

Ray

LaLaLisa · 09-21-2021, 10:22 PM

Quote:

Originally Posted by NXR

What is the intended use for solar? Just to keep the batteries topped off in storage? To boondock for days at a time or what?

It's not a question you asked however I would use an MPPT solar controller, not a PWM controller. An MPPT controller can "harvest" more power from your solar array because it's more efficient. If you use a PWM controller some of the dollars you put into sizing your solar array are wasted. That means you need to buy more solar to make up for the efficiency loss in a PWM controller.

https://www.victronenergy.com/blog/2...r-pwm-or-mppt/

Ray

We were thinking just as you mentioned, for storage and the occasional boondocking. We remember when we picked it up, the guy told us all we had to do was install the panels because everything else was already installed. There is a place near the power cord for the solar connection. I’ll check again when we take her out in a couple weeks. He made it sound like you put the panels on the rooftop, or had some to set aside when parked, and just plugged it in. Maybe I’m oversimplifying as this is certainly not my field.

NXR · 09-21-2021, 10:33 PM

Yup, that's it, that little Zamp socket. Worthless. You could plug in a portable panel but it could get stolen in a storage lot. The is no wiring provisions from the roof down to the batteries so you would be running that by yourself.

A friend just stuck a small panel in the windshield and plugged it into the cigarette lighter to keep the chassis battery topped off.

Ray

LaLaLisa · 09-22-2021, 06:34 AM

That's a good idea, thanks!

mjbenedict · 09-22-2021, 08:23 AM

Quote:

Originally Posted by LaLaLisa

We were thinking just as you mentioned, for storage and the occasional boondocking. We remember when we picked it up, the guy told us all we had to do was install the panels because everything else was already installed. There is a place near the power cord for the solar connection. I’ll check again when we take her out in a couple weeks. He made it sound like you put the panels on the rooftop, or had some to set aside when parked, and just plugged it in. Maybe I’m oversimplifying as this is certainly not my field.

"Solar ready" means they installed a cord connected to the battery and placed the hookup on the outside of the trailer. Think of it as an extension cord, nothing more.
You still need the controller and the panels. The "solar ready" hookup is best for an external panel with its own controller.
If you want a permanent install you should ignore this hookup and wire according to a solar kit's installation guidelines.

NXR · 09-22-2021, 09:45 AM

Quote:

Originally Posted by LaLaLisa

That's a good idea, thanks!

You just need to confirm that the power outlet supplies power even when the house batteries are off and the ignition is off.

If not, you could install an extra power outlet with a few hours work, one that is fused appropriately and installed where you need it.

Ray

Jc4ut · 09-23-2021, 05:37 PM

Quote:

Originally Posted by LaLaLisa

Hey Gang,
We are considering installing solar on our GT7 36D. It has the hookup, or so we were told, but we’re having trouble finding any information about how to do this. Any ideas from some of you with the identical house on wheels? Thanks!

I have watched every YouTube video about the gt7 and none say anything about a solar hookup connection. The brochure also says nothing about a solar panel but I’m going back and read it again. My GT 7 36d7 should arrive in December. I’ll let you know if I find anywhere it says the coach comes with solar connector. BRB

Jimbo

Jc4ut · 09-23-2021, 05:46 PM

Ok the brochure I just read says furrion solar prep. Will be interested to see where the connection is located!!!! I would Get a solar suitcase at 200 to 250 watts as they come with a controller and you can point it however you want. Good for boondocking or topping off batteries while in storage.

Jimbo

NXR · 09-23-2021, 09:40 PM

Quote:

Originally Posted by Jc4ut

I have watched every YouTube video about the gt7 and none say anything about a solar hookup connection. The brochure also says nothing about a solar panel but I’m going back and read it again. My GT 7 36d7 should arrive in December. I’ll let you know if I find anywhere it says the coach comes with solar connector. BRB

Beginning with the 2021.5 model year FR started installing a 115 watt solar panel on the roof plus a controller as standard.

Ray

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